We have a 2020 Nation, ready for a big trip. rig will start, but all 110 and 12 volt to unit off and generator won't

Hi! My name is ***** ***** I can assist you with this. I may need some additional information from you first in order to give a complete answer.

Good evening! I have an RV repair facility and work on these systems for a living. This sounds like perhaps a few things need checking. Start by checking the battery disconnect switch and be sure that the battery(s) are in the loop. Check the breaker on the generator and be sure that it isn't tripped. Be sure that all the breakers in load center are in the "On" position. Randall

I called and go no answer. Let me know when to call back. And it would be a good idea to go to the Winnebago Wiring Diagrams site and find this year and model and download all the wiring diagrams for this coach. Print them up and keep them in the coach. Get a small digital multimeter like they sell at most local hardware stores. About $20 or so and easy to use. A great tool to have when there is a problem like this. Randall

All that is shown in those wiring diagrams and the Owner's Manuals.

Please give me a call back again when you are ready to test. Have a good evening!